From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sat, 6 Mar 2021 11:02:18 +0000 (+0000)
Subject: io-wq: warn on creating manager while exiting
X-Git-Tag: v5.12-rc3~23^2~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=678eeba481d8c161203382832a4379d507050aed;p=thirdparty%2Fkernel%2Flinux.git

io-wq: warn on creating manager while exiting

Add a simple warning making sure that nobody tries to create a new
manager while we're under IO_WQ_BIT_EXIT. That can potentially happen
due to racy work submission after final put.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1bfdb86336e49..1ab9324e602f5 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -774,6 +774,8 @@ static int io_wq_fork_manager(struct io_wq *wq)
 	if (wq->manager)
 		return 0;
 
+	WARN_ON_ONCE(test_bit(IO_WQ_BIT_EXIT, &wq->state));
+
 	init_completion(&wq->worker_done);
 	atomic_set(&wq->worker_refs, 1);
 	tsk = create_io_thread(io_wq_manager, wq, NUMA_NO_NODE);